1. Field of the Invention
The invention relates to a clutch for a motor vehicle with a friction lining which can be clamped between two disks designed as contact-pressure disks and/or intermediate disks. The clutch is connected in a rotationally fixed manner to a first shaft and is used to produce frictional engagement between the first shaft and a second shaft connected in a rotationally fixed manner to the disks. At least one of the disks has driver elements which enter into an axial guide which has a stop for transmitting a torque to the driver element.
2. Description of the Related Art
A multi-disk dry clutch is known, for example, from DE 195 17 968. As the clutch is engaged, one of the contact-pressure disks moves in the direction of the other contact-pressure disk and preloads friction linings against a plurality of intermediate disks. During this process, the friction linings and the intermediate disks are displaced axially. During disengagement, the axially displaceable contact-pressure disk is relieved of load in the axial direction, with the result that the friction linings are separated from the intermediate disk and the contact-pressure disks. A clutch housing has a multiplicity of grooves to guide the contact-pressure disks and the intermediate disks axially. The contact-pressure disks and the intermediate disks have as a toothed driver element which enters into the grooves of the guide. The friction linings similarly have a driver element which engages in a form-fitting manner in an axial guide of a hub. The stops are each accordingly located on that side of the guide on which the driver elements are supported during power transmission by the clutch.
The disadvantage with the known multi-disk clutch is that the driver elements wear and can dig into the stops. During subsequent disengagement, this leads to the friction linings initially sticking in their position and rubbing against the intermediate disks and the fixed contact-pressure disk.
DE 34 37 741 A1 has disclosed a multi-disk clutch in which the intermediate disks each have spring elements and push away from one another during disengagement. This is intended to prevent adjacent intermediate disks from remaining in a state in which they clamp the friction linings. However, as in DE 195 17 968 A1, the axially movable disks have driver elements which enter into guides. The driver elements can dig into the stops of the guides and stick during disengagement.
The problem addressed by the invention is in configuring a clutch of the type stated at the outset in such a way that it reliably prevents sticking of the axially movable disks in the guides.
According to the invention, the aforementioned problem is solved by placing a spring element for moving the driver elements into a position remote from the stop.
By virtue of this configuration, the driver element (also referred to as a spring supported guided driver) is moved reliably away from the stop during the disengagement of the clutch, hence preventing it from sliding over the stop. Even if the driver elements dig into the stops in the engaged state due to the clutch torque, the driver element is initially moved perpendicularly away from the stop. The contact-pressure disks and the intermediate disks can then separate from the friction linings. With this configuration, the contact-pressure disks and the intermediate disks do not stick in the guide as the clutch is disengaged. By virtue of the invention, the friction linings can be prevented from rubbing against the contact-pressure disks and/or the intermediate disks. Another advantage of this configuration of the clutch is that the driver element is damped by the force of the spring element as it moves up against the stop during the engagement of the clutch. This allows particularly comfortable operation of the clutch according to the invention.
It is possible to secure the spring element on the clutch housing. However, the clutch according to the invention can be assembled in a particularly simple manner if the spring element is arranged on the driver element. As a result, a constructional unit comprising the spring element and the driver element can be preinstalled first. The prefabricated constructional unit can then be installed in the clutch housing as in the case of the known clutch.
The spring element could, for example, be configured as a tension spring that pulls the driver element away from the stop. However, according to another advantageous development of the invention, the spring element requires a particularly small amount of installation space and can furthermore be installed in a simple manner if the spring element is supported in the guide.
The spring element could, for example, be arranged between each of the driver elements and the stops and be completely compressed during the engagement of the clutch and transmission of a torque. However, in this configuration, the spring element may be plastically deformed and damaged. Damage to the spring element can be avoided in a simple manner if some of the driver elements are designed as protrusions which are narrow in comparison with the guide, and in each case at least one spring element is arranged on these driver elements. By virtue of this configuration, the spring travel of the spring element and an envisaged preload can be easily set.
The spring element could, for example, be configured as a spring tongue. However, according to an advantageous development of the invention, the spring element can preload the driver element over a very large distance if the spring element is of a meandering configuration.
According to another advantageous development of the invention, the components having the driver elements are preloaded reliably into an envisaged initial position if two spring elements with mutually opposite spring directions are arranged on each of the driver elements.
A contributory factor in further simplifying the assembly of the clutch according to the invention is for the driver element to bear a holding clip with a plurality of spring elements.
According to another advantageous development of the invention, the contact-pressure disks and/or the intermediate disks can simply be moved apart by a predetermined amount when disengaging the clutch if some of the spring elements are configured for support against an adjacent contact-pressure disk or intermediate disk. The contact-pressure disks and the intermediate disks are thereby preloaded in the axial and radial directions.
According to another advantageous development of the invention, the spring elements are secured reliably on the driver element if the holding clip has holding tabs provided to engage around the driver element.
According to another advantageous development of the invention, the holding clip and the spring elements can be configured in a particularly economical manner if the holding clip is produced in one piece with the spring elements and/or the holding tabs.
The invention allows for numerous embodiments. To further illustrate its basic principle, one of these is illustrated in the drawings and is described below.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.